1. Field of the Invention
This invention relates to an improved tool for extracting a microelectronic chip carrier from a receptacle to which it is connected.
2. Description of the Prior Art
Mounting of a chip carrier onto an appropriate receptacle is a relatively straight forward procedure. It merely requires an operator to align the contacts of the chip carrier with those of the mating receptacle, then press firmly against the receptacle until it is fully seated. In the instance in which the chip carrier has a plurality of outwardly extending pins, these pins must be firmly aligned with socket holes in the receptacle before pressing firmly against the chip carrier. However, extracting the chip carrier, is not merely as simple a procedure for a number of reasons.
In the first instance, the chip carriers are small and generally difficult to grasp. Furthermore, if too much pressure is applied to the outer casing of the carrier, it can become cracked and thereby probably rendered useless. Additionally, chip carriers are often mounted on densely packed receptacles, printed circuit boards, for example, such that they are closely surrounded by other components. Then, too, if the chip carrier is not drawn outwardly in a careful manner such that a plane of the chip carrier remains generally parallel with that of the circuit board, the contacts can become bent and therefore misaligned, such that, following a subsequent insertion, they will not operate in an effective manner.
To effect extraction of a chip carrier from a receptacle without damage to either component, a number of tools have previously been devised. For example, Burndy Corporation, of Norwalk, Conn., presently manufactures and sells extraction tools referred to by catalog numbers QILE68EX-1 and QILE84EX-1. This design is of the screw type and requires a different size of extraction device for each different size of chip carrrier. For example, in the instance of the first catalog number cited above, the tool is operable to extract 68 contact chip carriers while the latter design is effective to extract 84 contact tool carriers.
Another extraction tool also manufactured by Burndy Corporation is that known by catalog number QILE68EX-2. In this instance, the tool includes a base with a depending skirt to define an underneath recess. Centrally upstanding from the upper surface of the base is an integral thumb receiving post. A spring member with a pair of opposed tong receiving loops located to either side of the post passes slidably through a vertical slot in the post. Each loop is curved outwardly and downwardly and extends through holes adjacent opposite corners in the base and terminates at a hook for engaging a chip carrier. When the base is grasped and the spring members pushed downwardly, the chip carrier engaging hooks extend beyond the terminal rim of the pending skirt. Then holding the tool by the sides of the springs, the tool is placed over the socket supporting a chip carrier and the hooks are appropriately positioned to straddle the chip carrier. Thereupon, the thumb receiving post is pushed downwardly toward the socket which serves to extend the tool skirt over the side of the socket and the socket into the recess defined by the skirt. While maintaining downward pressure on the knob, the operator then pulls the two loops of the spring member upwardly to extract the chip carrier from its socket. The tool is then lifted from the socket carrying with it the extracted chip carrier. Thereupon, the chip carrier is released from the tool by setting the tool on a soft surface and pushing down on the spring.
Another known tool is manufactured and sold by AMP Inc. of Harrisburg, PA, known by catalog number 821566-1, also known as AMP "68", which is capable of extracting a carrier chip with 68 connectors. This too, is capable of extracting only one size of chip carrier, for example, a carrier whose chip has 68 contacts. As with the other constructions, this tool also has a pair of spaced apart hooks extending from the main body of the tool. The hooks are operated by opposed handles which pivot on spaced apart axes. The handles have matingly engaging arcuate surfaces which operate a suitable cam and follow mechanism to cause the hooks to compress on the sides of the chip carrier; then, when the operator continues to squeeze the handles together, the hooks engage the undersurface of the chip carrier and draw it away from the receptacle in which it had been positioned.
Still another extraction tool which has previously been used in a tweezers type tool which is manufactured by Microelectronics Supplies Inc., of Danbury, Conn. and identified by catalog number QILE--EX-3. In this instance, inwardly directed hooks at the extreme ends of the device straddle the chip carrier and are moved by the operator to engage both the sides and the undersurface of the chip carrier. With the tool squeezed against the chip carrier, the operator pulls in a direction away from the receptacle on which the chip carrier is mounted to thereby extract the chip carrier from the receptacle.
Still another extractor tool is manfactured by Techni-Tool of Plymouth Meeting, Pa. under the trademark "LITTLE GRIPPER". This latter tool is a DIP (i.e. "dual in-line pin") extraction tool which has opposed rows of teeth which can be extended from a handle portion to engage the carrier unit when the teeth are aligned with spaces between the DIP leads. The extraction device is then locked onto the DIP and, by using a T-bar fixed to a slide member which extends through the housing and is integral with the tong member, is then raised to thereby draw the connector off the receptacle to which it was previously mounted.
Yet another extractor tool known to the Inventor is manufactured by SAMTEC of New Albany, Ind. This tool is cam actuated and acts on all four sides of a pin grid array at one time.
It was with knowledge of the current state-of-the-art as represented by the extraction tools just described that the present invention was conceived and has now been reduced to practice.